Effects of tobacco growing on tree species diversity and composition: A case study of Kabwoya Sub-County, Kikuube District

Abstract

Tobacco is now widely grown as a cash crop in developing countries like Uganda, but faces unregulated destruction of trees which is not compatible with SDG goal 13 and 15. However, comprehensive studies about the tobacco deforestation ecological effects are limited. This study therefore, sought to archive three objectives; (1) To determine the spatial extent and changes in tobacco between the year 2010 and 2020 in Kabwoya Sub County. (2) To analyze changes in tree species and composition due to tobacco growing. (3) To establish community strategies for regulating tree utilization amidst expanding tobacco production. 2010 and 2020 cloud free land sat images downloaded from USGS were pre-processed. The images were then subjected to supervised classification of six classes (water, swamps, dense vegetation, sparse vegetation, tobacco, built-up and open surfaces) using ArcMap V10.7.1 as to come up with details on land use cover changes and extent. Data on tree species, number of stumps and live trees from both tobacco and non-tobacco plots were recorded along the transects measuring 200 meters, and sample plots of 10 m by 10 m, 5 plots in total were established along each transect. A total of 44 tobacco and non-tobacco households were sampled for the study to obtain the past changes in tree species due to tobacco growing. Key informant interviews were also conducted targeting local elders and focal person within Kabwoya sub county. The results show that the area under tobacco cover in 2010 was 14110ha but increased in 2020 to 15807ha. This represents an increase by 1.47%. Number of tree species found in non-tobacco plots were higher than tree species in tobacco plots and the number of tree stumps were higher in tobacco gardens compared to non-tobacco plots. Indigenous trees have been cut down and restoration programs are not effective hence replacing the indigenous tree species with exotic tree species. However, the study also revealed that there are some measures arising to regulate tree utilization such as re-afforestation, shifting from tobacco growing to cattle rearing. It is recommended that there is need for energy substitution by stake holders mores especially Uganda Tobacco Services Limited to reduce over dependence on wood fuel and encourage more afforestation programs with in Kabwoya sub county.